Three major aspects of gene expression and regulation in human cells productively infected with herpes simplex virus type I (HSV-1) will be investigated: 1) Virus-induced changes in cytoplasmic low molecular weight (lmw) RNAs: The virus-induced shut-off of host 4S and 7S RNAs, the synthesis of HSV-specific lmw RNAs, and the role of lmw RNA alterations in the regulation of viral and host gene expression will be studied. 2) The DNA-dependent RNA polymerases involved in the transcription of HSV DNA: Using systems of isolated nuclei and enzymes, the polymerase forms present in HSV infected cells will be identified, isolated, characterized, and compared with those of the uninfected cell. The RNA polymerases and any viral encoded transcriptional components which are involved in the transcription of the different classes of HSV genes will be elucidated. 3) Primary transcription, processing, and transport of HSV RNA: These studies will include a complete characterization of HSV-specific transcripts found in the cytoplasm and nuclei of infected cells; characterization of HSV transcription units, primary transcripts and promoters; investigation of the molecular mechanisms involved in the processing and transport of viral RNA molecules. BIBLIOGRAPHIC REFERENCES: Silverstein, S., Millette, R.L., Jones, P., and Roizman, B. RNA Synthesis in Cells Infected with Herpes Simplex Virus. XII. Sequence Complexity and Properties of RNA differing in Extent of Adenylation. J. Virol. 18, 977 (1976). Ali, R., Millette, R.L., and Sauerbier, W. End Group Analysis of Naturally and UV Lesion Terminated T7 in vitro RNA. Nucleic Acids Res. 3, 3359 (1976).